Additional Rear-side Global POA Irradiance Adjustments (IAM, Soiling, & Spectral; Far Shadings?)

[kjs55]

Hi, Are there any plans to include rear-side IAM, soiling, or spectral adjustments in calculating global plane-of-array POA effective irradiance on the rear side of bifacial PV modules (in addition to the existing near shadings for rear-side global POA incident irradiance already taken into account within the PVsyst bifacial view factor model)? Regarding the latter (spectral), reportedly there are bifacial CdTe PV modules in development & coming soon to the market.

P.S. I need to check the PVsyst Help Menu on whether far shadings are already taken into account (for rear-side Global POA Incident Irradiance); if not, I'd like to add this to my above question.

Edited May 6, 2022 by kjs55
Slight grammar edits

[dtarin]

IAM is automatically included using plain glass fresnel option. They are reviewing whether to include this as a separate loss factor so as to be able to determine rear POA before all loss considerations. 

[kjs55]

@dtarin: Thanks for weighing in on that one point. Here's a reference I found to support your first claim: https://www.pvsyst.com/help/iam_loss.htm

[Michele Oliosi]

dtarin is correct, this is the current state of affairs.

Regarding the spectral correction, I doubt this would come up soon. The effect of ground refelction on the spectrum of light seems complex to model (and maybe for a small impact overall?). Do you have any references on this topic ?

Finally soiling is quite similar to backside shading, you can increase the percentage for backside shadings (one of the parameters in the bifacial model) to take this into account.